linux恢复 rm -rf * 误删数据

墨蓝 2022-02-27 08:24 863阅读 0赞

### linux恢复 rm -rf \* 误删数据 ###

*   *  一、磁盘分区挂载为只读
     *   *  1、查看被删除文件位于哪个分区
         *  2、将对应目录重新挂载为只读
     *  二、安装数据恢复工具 extundelete
     *   *  1、下载extundelete-0.2.4
         *  2、安装
     *  三、恢复
     *   *  1、模拟删除文件，设置只读
         *  2、查看被删除的文件
         *  3、恢复
         *  4、重新挂载分区为读写

linux误删除文件后应尽快将磁盘挂载为只读，否则后续操作可能会覆盖这些数据，越早发现，并挂载为只读，恢复的成功机率就越大。因此，本文只是提供一种方式，不能保证一定能恢复误删的数据。

## 一、磁盘分区挂载为只读 ##

### 1、查看被删除文件位于哪个分区 ###

[root@localhost ~]# mount
    /dev/sda3 on / type ext4 (rw)
    /dev/sda1 on /boot type ext4 (rw)
    /dev/sdb1 on /opt type ext4 (rw)

### 2、将对应目录重新挂载为只读 ###

[root@localhost  ~]#  mount -r -n -o remount /opt
    mount: /home is busy

如果显示 xxx is busy
    [root@localhost  ~ ]# fuser -v -m /opt

找出相关进程，kill掉

[root@localhost  ~ ] #  mount -r -n -o remount /opt

成功后，此时在/opt目录 touch文件时，会报错：

[root@localhost  opt ] # touch txt
    touch: cannot touch `txt’: Read-only file system

## 二、安装数据恢复工具 extundelete ##

### 1、下载extundelete-0.2.4 ###

下载源：  
http://superb-dca2.dl.sourceforge.net/project/extundelete/extundelete/0.2.4/extundelete-0.2.4.tar.bz2

### 2、安装 ###

需要安装编译环境及extundelete依赖的包  
yum -y install gcc+ gcc-c++  
yum install e2fsprogs e2fsprogs-libs e2fsprogs-devel -y

[root@localhost extundelete-0.2.4]# ./configure 
    Configuring extundelete 0.2.4
    Writing generated files to disk
    [root@localhost extundelete-0.2.4]# make
    make -s all-recursive
    Making all in src
    [root@localhost extundelete-0.2.4]# make install
    Making install in src
      /usr/bin/install -c extundelete '/usr/local/bin'
    [root@localhost extundelete-0.2.4]# cd src/     --验证
    [root@localhost src]# ./extundelete -v
    extundelete version 0.2.4
    libext2fs version 1.41.12
    Processor is little endian.
    [root@localhost src]#

到此安装完成！

## 三、恢复 ##

### 1、模拟删除文件，设置只读 ###

[root@localhost src]# cd /opt/
    [root@localhost opt]# ls
    lost+found  test
    [root@localhost opt]# cd test/
    [root@localhost test]# ls
    1.txt  extundelete-0.2.4.tar.bz2
    [root@localhost test]# more 1.txt 
    ceshi
    test
    qazwsx
    edcrfv
    tgbyhn
    ujmik,
    [root@localhost test]# cd ..
    [root@localhost opt]# rm -rf test/
    [root@localhost opt]# cd ..
    [root@localhost /]# mount -r -n -o remount /opt

### 2、查看被删除的文件 ###

[root@localhost /]# extundelete /dev/sdb1 --inode 2
    NOTICE: Extended attributes are not restored.
    Loading filesystem metadata ... 400 groups loaded.
    Group: 0
    Contents of inode 2:
    Inode is Allocated
    File mode: 16877
    Low 16 bits of Owner Uid: 0
    Size in bytes: 4096
    Access time: 1553670589
    Creation time: 1553672852
    Modification time: 1553672852
    Deletion Time: 0
    Low 16 bits of Group Id: 0
    Links count: 3
    Blocks count: 8
    File flags: 0
    File version (for NFS): 0
    File ACL: 0
    Directory ACL: 0
    Fragment address: 0
    Direct blocks: 9249, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
    Indirect block: 0
    Double indirect block: 0
    Triple indirect block: 0
    
    File name                                       | Inode number | Deleted status
    .                                                 2
    ..                                                2
    lost+found                                        11
    test                                              1835009        Deleted

一个分区挂载到一个目录下时，”根”目录的inode值为一般是2。

状态为deleted的是被删除的文件，可以看到模拟删除的文件test

### 3、恢复 ###

确定删除的大概时间，可以较快的恢复误删的数据

[root@localhost /]# date -d "Wed Mar 26 15:40:00 CST 2019" +%s
    1553586000

执行恢复命令（在另外的磁盘分区执行恢复）

[root@localhost /]# /extundelete-0.2.4/src/extundelete /dev/sdb1 --after 1553586000 --restore-all
    Only show and process deleted entries if they are deleted on or after 1553586000 and before 9223372036854775807.
    NOTICE: Extended attributes are not restored.
    Loading filesystem metadata ... 400 groups loaded.
    Loading journal descriptors ... 78 descriptors loaded.
    Searching for recoverable inodes in directory / ... 
    5 recoverable inodes found.
    Looking through the directory structure for deleted files ... 
    1 recoverable inodes still lost.

恢复完成，验证

[root@localhost /]# cd RECOVERED_FILES/
    [root@localhost RECOVERED_FILES]# ls
    test
    [root@localhost RECOVERED_FILES]# cd test/
    [root@localhost test]# ls
    1.txt  extundelete-0.2.4.tar.bz2
    [root@localhost test]# more 1.txt 
    ceshi
    test
    qazwsx
    edcrfv
    tgbyhn
    ujmik,
    [root@localhost test]#

可以看到删除的文件已经恢复。

### 4、重新挂载分区为读写 ###

[root@localhost test]#mount -rw  -o remount /opt

可以对rm启用别名，防止无交互删除

vi /etc/bashrc

\#do not delete / or prompt if deleting more than 3 files at a time \#  
alias rm=‘rm -I --preserve-root’

source /etc/bashrc

***ext3grep、debugfs也可以恢复误删文件，还需再研究***

附：extundelete相关参数

[root@localhost test]# /extundelete-0.2.4/src/extundelete 
    No action specified; implying --superblock.
    /extundelete-0.2.4/src/extundelete: Missing device name.
    Usage: /extundelete-0.2.4/src/extundelete [options] [--] device-file
    Options:
      --version, -[vV]       Print version and exit successfully.
      --help,                Print this help and exit successfully.
      --superblock           Print contents of superblock in addition to the rest.
                             If no action is specified then this option is implied.
      --journal              Show content of journal.
      --after dtime          Only process entries deleted on or after 'dtime'.
      --before dtime         Only process entries deleted before 'dtime'.
    Actions:
      --inode ino            Show info on inode 'ino'.
      --block blk            Show info on block 'blk'.
      --restore-inode ino[,ino,...]
                             Restore the file(s) with known inode number 'ino'.
                             The restored files are created in ./RECOVERED_FILES
                             with their inode number as extension (ie, file.12345).
      --restore-file 'path'  Will restore file 'path'. 'path' is relative to root
                             of the partition and does not start with a '/'
                             The restored file is created in the current
                             directory as 'RECOVERED_FILES/path'.
      --restore-files 'path' Will restore files which are listed in the file 'path'.
                             Each filename should be in the same format as an option
                             to --restore-file, and there should be one per line.
      --restore-directory 'path'
                             Will restore directory 'path'. 'path' is relative to the
                             root directory of the file system.  The restored
                             directory is created in the output directory as 'path'.
      --restore-all          Attempts to restore everything.
      -j journal             Reads an external journal from the named file.
      -b blocknumber         Uses the backup superblock at blocknumber when opening
                             the file system.
      -B blocksize           Uses blocksize as the block size when opening the file
                             system.  The number should be the number of bytes.
      --log 0                Make the program silent.
      --log filename         Logs all messages to filename.
    --log D1=0,D2=filename   Custom control of log messages with comma-separated
       Examples below:       list of options.  Dn must be one of info, warn, or
       --log info,error      error.  Omission of the '=name' results in messages
       --log warn=0          with the specified level to be logged to the console.
       --log error=filename  If the parameter is '=0', logging for the specified
                             level will be turned off.  If the parameter is
                             '=filename', messages with that level will be written
                             to filename.
       -o directory          Save the recovered files to the named directory.
                             The restored files are created in a directory
                             named 'RECOVERED_FILES/' by default.